The U.S. Justice Department agreed to clear
CenturyLink Inc.
CTL -4.66%
’s $25 billion takeover of
Level 3 Communications Inc.
if the telecom providers shed some of their fiber-optic infrastructure, moving the deal one step closer to closing.

A consent decree filed Monday in the U.S. District Court for the District of Columbia allowed the internet service providers to combine operations provided that Level 3 sells some assets around Albuquerque, N.M.; Boise, Idaho; and Tucson, Ariz.

The companies must also sell 24 strands of long-distance “dark” fiber not in use. Such lines usually go to telecom companies at the internet’s core, though web companies such as Google owner Alphabet Inc. and
Facebook Inc.
have built their own network backbones in recent years.

The agreement comes after the Senate last week confirmed President
Donald Trump
’s nominee to head the Justice Department’s antitrust division, Makan Delrahim, after months of delay.

CenturyLink and Level 3 unveiled their cash-and-stock merger last year. Executives said joining forces would allow the telecom companies to cut costs and compete more effectively against bigger rivals.

Both companies could use the operational boost. Revenue has slid over the past year, especially at CenturyLink, as customers abandon traditional landlines and as prices for raw internet bandwidth decline. The new company’s greater size is designed to appeal to larger corporate clients, including big technology companies seeking to link their own networks.

The deal still needs nods from the Federal Communications Commission and the California Public Utilities Commission.